Interleukin-1ß secretion in hippocampal sclerosis patients with mesial temporal lobe epilepsy.

Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is a common medically intractable epilepsy syndrome. Although pathogenesis of HS still remains highly controversial, genetics may play a role as a predisposing factor. Previous evidence in a Japanese population revealed that the homozygotes for allele T at position -511 of the interleukin (IL)-1ß gene promoter region (IL-1ß-511 T/T) confers susceptibility to the development of HS. However, whether this polymorphism has an effect on IL-1ß levels in MTLEHS patients was not demonstrated. This study aimed to analyze the distribution of this particular polymorphism in a group of Turkish HS patients and correlate the polymorphism with IL-1ß secretion from the lymphocytes, thus revealing a functional role for IL-1ß in the etiopathogenesis of HS. A single base pair polymorphism at position -511 in the promoter region of the IL-1ß gene was analyzed. The spontaneous and 1 ng/mL lipopolysaccharidestimulated production of IL-1ß by peripheral blood mononuclear cells after 4 and 24 h of incubation were measured by ELISA method. The heterozygous type (-511 C/T) was the most common genotype. There was no difference in frequency of allele -511 T between patients and controls. Analysis of IL-1ß levels, genotype and allele distributions showed no significant difference among the groups (P>0.05). Nevertheless, it was seen that patients who carry a T allele at position -511 of the IL-1ß gene had increased IL-1ß levels. T-allele carriage may be important. Only IL-1ß secretion from the lymphocytes has been assessed in this study. Considering the importance of IL-1ß in the etiopathogenesis of HS, further studies are needed to evaluate locally produced IL-1ß levels.

Tbx3 represses PTEN and is over-expressed in head and neck squamous cell carcinoma.

BACKGROUND: Despite advances in diagnostic and treatment strategies, head and neck squamous cell cancer (HNSCC) constitutes one of the worst cancer types in terms of prognosis. PTEN is one of the tumour suppressors whose expression and/or activity have been found to be reduced in HNSCC, with rather low rates of mutations within the PTEN gene (6-8%). We reasoned that low expression levels of PTEN might be due to a transcriptional repression governed by an oncogene. Tbx2 and Tbx3, both of which are transcriptional repressors, have been found to be amplified or over-expressed in various cancer types. Thus, we hypothesize that Tbx3 may be over expressed in HNSCC and may repress PTEN, thus leading to cancer formation and/or progression. METHODS: Using immunohistochemistry and quantitative PCR (qPCR), protein and mRNA levels of PTEN and Tbx3 were identified in samples excised from cancerous and adjacent normal tissues from 33 patients who were diagnosed with HNSCC. In addition, HeLa and HEK cell lines were transfected with a Tbx3 expressing plasmid and endogenous PTEN mRNA and protein levels were determined via qPCR and flow cytometry. Transcription assays were performed to demonstrate effects of Tbx3 on PTEN promoter activity. Mann-Whitney, Spearman's Correlation and Wilcoxon signed-rank tests were used to analyze the data. RESULTS: We demonstrate that in HNSCC samples, Tbx3 mRNA levels are increased with respect to their normal tissue counterparts (p<0.001), whereas PTEN mRNA levels are significantly reduced in cancer tissues. Moreover, Tbx3 protein is also increased in HNSCC tissue sections. Over-expression of Tbx3 in HeLa and HEK cell lines causes reduction in endogenous PTEN mRNA and protein levels. In addition, transcription activity assays reveal that Tbx3 is capable of repressing both the basal and induced promoter activity of PTEN. CONCLUSIONS: We show that Tbx3 is up-regulated in tissue samples of HNSCC patients and that Tbx3 represses PTEN transcription. Thus, our data not only reveals a new mechanism that may be important in cancer formation, but also suggests that Tbx3 can be used as a potential biomarker in cancer.

Interleukin-6 gene polymorphism in febrile seizures.

Febrile seizures comprise a common type of pediatric convulsion. Inflammation and genetics may be involved in their pathogenesis. Regarding the role of cytokines (especially interleukin-6) in febrile responses, we performed a case control study of interleukin-6 gene (-174, -572, and -597) single-nucleotide polymorphisms to learn if correlations existed between these particular polymorphisms and febrile seizures. We isolated the genomic DNA of 92 children with febrile seizures and 98 healthy control subjects. We genotyped individuals for their polymorphisms, using polymerase chain reaction-restriction fragment length polymorphism. In our study, the frequencies of -174 G alleles and of the -174 and -572 GG genotypes were observed to be significantly higher in patients than in control subjects. The -174 GG genotype frequency was significantly higher in children with a family history of febrile seizures.

VEGF polymorphisms and serum VEGF levels in Parkinson's disease.

Accumulated data within the recent years demonstrate that reduced levels of VEGF which is a well known angiogenic molecule might cause neurodegeneration in part by impairing neural tissue perfusion, vasoregulation and normal functioning of perivascular autonomic nerves. Additionally, VEGF has been reported to support neuroprotection in dopaminergic neurons by indirect and direct mechanisms and suppress apoptosis in dopaminergic neurons in vitro. The aim of the current study is first to demonstrate whether there is an association between the three common VEGF polymorphisms (-2578C/A, -634C/G and 936C/T) in the VEGF gene and idiopathic Parkinson's disease (IPD) which is a neurodegenerative disease caused by the progressive degeneration of nigrostriatal dopaminergic neurons, and second to see if the serum levels of VEGF is reduced in the patients with IPD. We screened the genotype and allele frequencies of three common functional polymorphisms of VEGF, namely -2578C/A, -634C/G and 936C/T in DNA samples of 126 patients with IPD and healthy control subjects and also we compared the median serum levels of VEGF between these two groups. No association was found between the inspected VEGF polymorphisms and IPD and also no difference was found between the serum VEGF levels of both groups. The current study failed to support the hypothesis that VEGF polymorphisms and/or reduced serum VEGF levels are likely contributors to the neurodegenerative process in IPD.

Nitric oxide generation by endothelial cells exposed to shear stress in glass tubes perfused with red blood cell suspensions: role of aggregation.

Endothelial function is modulated by wall shear stress acting on the vessel wall, which is determined by fluid velocity and the local viscosity near the vessel wall. Red blood cell (RBC) aggregation may affect the local viscosity by favoring axial migration. The aim of this study was to investigate the role of RBC aggregation, with or without altered plasma viscosity, in the mechanically induced nitric oxide (NO)-related mechanisms of endothelial cells. Human umbilical vein endothelial cells (HUVEC) were cultured on the inner surface of cylindrical glass capillaries that were perfused with RBC suspensions having normal and increased aggregation at a nominal shear stress of 15 dyn/cm(2). RBC aggregation was enhanced by two different approaches: 1) poloxamer-coated RBC suspended in normal, autologous plasma, resulting in enhanced aggregation but unchanged plasma viscosity and 2) normal RBC suspended in autologous plasma containing 0.5% dextran (mol mass 500 kDa), with a similar level of RBC aggregation but higher plasma viscosity. Compared with normal cells in unmodified plasma, perfusion with suspensions of poloxamer-coated RBC in normal plasma resulted in decreased levels of NO metabolites and serine 1177 phosphorylation of endothelial nitric oxide synthase (eNOS). Perfusion with normal RBC in plasma containing dextran resulted in a NO level that remained elevated, whereas only a modest decrease of phosphorylated eNOS level was observed. The results of this study suggest that increases of RBC aggregation tendency affect endothelial cell functions by altering local blood composition, especially if the alterations of RBC aggregation are due to modified cellular properties and not to plasma composition changes.

Relationship between periodontal findings and specific polymorphisms of interleukin-1alpha and -1beta in Turkish patients with Behçet's disease.

Genetic factors predispose individuals to Behçet's disease (BD) and periodontal disease. IL-1 has been implicated in the pathogenesis of both BD and periodontal disease. The relationship between periodontitis and pathogenesis of BD has not yet been determined. Since IL-1 has been implicated in the pathogenesis of both BD and periodontal disease, we aimed to investigate the possible relation of the periodontal scores and SNPs of IL-1alpha-889C/T, IL-1beta-511C/T, and IL-1beta+3962T/C with BD compared to healthy controls (HC) and recurrent aphtous stomatitis (RAS). A total of 155 Turkish individuals were enrolled in this study. The periodontal status of all subjects was evaluated according to the WHO community periodontal index of treatment needs. For genotyping, CTS-PCR-SSP was employed. IL-1alpha-889C allele was significantly higher in BD patients (p = 0.03) and RAS (p = 0.02) compared to HC. The frequency of IL-1beta+3962T allele was significantly higher in RAS patients compared to HC (p = 0.015). Male gender (p = 0.04), age (p = 0.02) and carrying IL-1beta-511T allele (p = 0.01) were found to be a significant risk factors for higher periodontal scores in Turkish population. We can speculate that susceptibility to the development of periodontal disease could be influenced by IL-1 SNPs. Periodontitis-induced autoinflammatory response also may play a role in the development/severity of BD and RAS via IL-1 gene alteration.

Interferon-gamma gene+874T-A polymorphism is associated with tuberculosis and gamma interferon response.

Interferon-gamma is the most important cytokine in resistance to mycobacterial diseases and common variants of interferon-gamma gene could be related to tuberculosis susceptibility. We tested the hypothesis that the interferon-gamma+874T-A polymorphism is associated with tuberculosis disease, and affects the interferon-gamma response. We determined by pyrosequencing the distribution of the interferon-gamma+874T-A polymorphism in a Turkish population of 319 patients with pulmonary tuberculosis, 42 children with severe forms of tuberculosis and 115 healthy donors. We also analysed whether any correlation exists between this polymorphism and interferon-gamma response to Mycobacterium tuberculosis antigens by ELISPOT in 58 pulmonary tuberculosis cases, and the results were analysed according to the genotypes. We found that the minor allele (T) frequency was significantly lower in patients with pulmonary tuberculosis when compared to controls (P=0.024, OR=0.7), a similarly significant decrease in the frequency of TT genotype was observed in patients with pulmonary tuberculosis, compared to the control group (P=0.02, OR=0.49). IFN-gamma responses to PPD antigen in TT genotype was found to be significantly higher than the AA group (P>0.001). Non-parametric correlation analysis of ELISPOT data showed significant reverse correlation in PPD, CFP10 and ESAT6 values and IFN-gamma +874 genotypes. These results show that the IFN-gamma +874T-A polymorphism is related to the IFN-gamma response and the magnitude of the response decreases during transition from TT- to TA and to AA genotypes. Our data suggest that similar to various Caucasian populations, in a Turkish population the IFN-gamma+874 T-A polymorphism is also associated with tuberculosis disease and affects the magnitude of the IFN-gamma response.

Specific interleukin-1 gene polymorphisms in Turkish patients with Behçet's disease.

Genetic factors that predispose individuals to Behçet's disease (BD) are considered to play important roles in the development of the disease. The pro-inflammatory cytokine interleukin-1 (IL-1) has been implicated in the pathogenesis of BD. Our aim was to determine a possible association of specific polymorphisms of IL-1alpha, IL-1beta, and IL-1 receptor antagonist genes with susceptibility for BD. We genotyped 72 patients with BD and 163 healthy controls for IL-1alpha-889, IL-1beta-511, and +3953 (nt5887) single-nucleotide polymorphisms besides IL-1 receptor antagonist variable number of tandem repeat polymorphism (for five different alleles). Comparison of the IL-1beta+3953 T allele and TT genotype frequencies showed a significant difference between patients with BD and controls (54.2 vs. 40.5%, OR = 1.74, P = 0.024, and 40.3 vs. 19.6%, OR = 2.76, P = 0.009, respectively). However, no difference was observed in the genotype or allele frequencies of IL-1alpha-889, IL-1beta-511, and IL-1 receptor antagonist between the patients with BD and the controls. Our results indicate that susceptibility to BD is increased in individuals carrying the IL-1beta+3953 T allele and TT genotype.

Saccharomyces cerevisiae C1D is implicated in both non-homologous DNA end joining and homologous recombination.

C1D is a gamma-irradiation inducible nuclear matrix protein that interacts with and activates the DNA-dependent protein kinase (DNA-PK) that is essential for the repair of the DNA double-strand breaks and V(D)J recombination. Recently, it was demonstrated that C1D can also interact with TRAX and prevent the association of TRAX with Translin, a factor known to bind DNA break-point junctions, and that over expression of C1D can induce p53-dependent apoptosis. Taken together, these findings suggest that mammalian C1D could be involved in maintenance of genome integrity by regulating the activity of proteins involved in DNA repair and recombination. To obtain direct evidence for the biological function of C1D that we show is highly conserved between diverse species, we have analysed the Saccharomyces cerevisiae C1D homologue. We report that the disruption of the YC1D gene results in a temperature sensitivity and that yc1d mutant strains exhibit defects in non-homologous DNA end joining (NHEJ) and accurate DNA repair. In addition, using a novel plasmid-based in vivo recombination assay, we show that yc1d mutant strains are also defective in homologous recombination. These results indicate that YC1D is implicated in both homologous recombination and NHEJ pathways for the repair of DNA double-strand breaks.

DNA damage-dependent interaction of the nuclear matrix protein C1D with Translin-associated factor X (TRAX).

The nuclear matrix protein C1D is an activator of the DNA-dependent protein kinase (DNA-PK), which is essential for the repair of DNA double-strand breaks (DSBs) and V(D)J recombination. C1D is phosphorylated very efficiently by DNA-PK, and its mRNA and protein levels are induced upon gamma-irradiation, suggesting that C1D may play a role in repair of DSBs in vivo. In an attempt to identify the biological function of C1D, we have employed the yeast two-hybrid system and found that C1D interacts specifically with Translin-associated factor X, TRAX. Although the biological function of TRAX remains unknown, its bipartite nuclear targeting sequences suggest a role for TRAX in the movement of associated proteins, including Translin, into the nucleus. We show that C1D and TRAX interact specifically in both yeast and mammalian cells. Interestingly, however, interaction of these two proteins in mammalian cells only occur following gamma-irradiation, raising the possibility of involvement of TRAX in DNA double-strand break repair and providing evidence for biological functions of the nuclear matrix protein C1D and TRAX. Moreover, we show, using fluorescently tagged proteins, that the relative expression levels of TRAX and Translin affect their subcellular localization. These results suggest that one role for C1D may be to regulate TRAX/Translin complex formation.